JP7322452B2 - Silicone rubber composite and method for producing the same - Google Patents

Description

The present invention relates to various mold release materials and slides used in the molding of display/touch panel related product members, LED lighting product members, movement/biological function measurement members, etc., such as ICs, passive components, and semiconductors incorporated in electrical and electronic products. The present invention relates to a silicone rubber composite excellent in elasticity, smoothness, soft touch, etc., which can be suitably used as a stopper (hereinafter referred to as "sealing material").

Silicone rubber has been conventionally used for applications such as the above-mentioned sealing materials because of its excellent heat resistance and electrical properties.

However, if you try to use a sheet made of silicone rubber alone as a release material for press molding, it will deform because it is a rubber product, resulting in poor assembly dimensional accuracy and wrinkles. I had a sexual problem.
Therefore, in order to solve the above-mentioned problems, it has been studied to combine and integrate a single silicone rubber and a plastic film. As a result, in addition to workability such as wrinkles and close contact, a long composite can be easily obtained, and it can be used for efficient roll-to-roll production.

As one method of compositing, there is a method of compositing pre-crosslinked silicone rubber and a plastic film via an adhesive, a method of bonding double-sided tape or applying an adhesive, etc., to conjugate via an adhesive layer. There is a way. In this case, an adhesive or pressure-sensitive adhesive for silicone rubber is usually used, but it is necessary to apply the adhesive or pressure-sensitive adhesive separately. I had an inconvenience.

Furthermore, in order to solve such problems, it has been studied to coat a plastic film with a silicone-based primer, attach an uncrosslinked silicone rubber to the plastic film, and then heat-crosslink the plastic film and integrate it with the silicone rubber at the same time. However, when the plastic film contains a crystalline polyester resin as a main component, the adhesiveness between the silicone-based primer and the plastic film is poor, and problems such as peeling tend to occur in the resulting composite.

Also, if the plastic film has low heat resistance, it cannot be applied because heat is applied during crosslinking of the silicone rubber. Furthermore, there is a problem that curling occurs in the resulting composite due to the large difference in thermal expansion between the plastic film and the silicone rubber.
In addition, since the thickness accuracy is not sufficient, when the plastic film is stacked or accumulated in a roll shape, wrinkles and bends occur as the amount of accumulation increases, and it does not return to its original shape. It was difficult to use.

As a silicone rubber composite that can solve the above-mentioned problems, Patent Document 1 discloses that a film containing a crystalline polyester resin as a main component is coated on at least one side with an undercoat layer and a silicone resin that has a high affinity for the undercoat layer. A silicone rubber composite has been proposed in which thin film layers are formed in order, a silicone rubber layer made of a silicone elastomer resin having a specific hardness is formed, and the film and the silicone rubber layer are integrated.

JP-A-11-20082

However, when the silicone composite of Patent Document 1 is used as a release material for press molding related to electrical and electronic product members, depending on the conditions, the thickness accuracy of the resulting molded member is not sufficient, and traces of air bubbles and wrinkles appear. In some cases, problems occurred, resulting in insufficient yield and productivity, and specific improvements were desired.
Furthermore, when the silicone rubber composite is used in the form of a sheet or a roll, when the silicone rubber composites are stacked, the substrate layer and the silicone rubber layer are in too close contact, making it difficult for the silicone rubber composite to peel off, resulting in poor workability. I had a problem with the drop.

An object of the present invention is to provide a silicone rubber composite having good workability, such that the silicone rubber composites are easily separated from each other when the silicone rubber composites are stacked when used in the form of sheets or rolls.

As a result of intensive studies to solve the above-described problems, the present invention found that by adjusting the center line average roughness of the other side of the substrate layer (A layer), which is different from the one side of the substrate layer (A layer), the silicone rubber composites can be separated from each other. This resulted in the completion of a silicone-rubber composite that is easily peeled off.

That is, the present invention provides an undercoat layer (B layer) containing an amorphous polymer and a thin film layer (C layer) containing a silicone resin on one side of a substrate layer (A layer) containing a crystalline polyester resin as a main component. ), and a silicone rubber layer (D layer) containing a silicone elastomer resin, which is laminated in this order and integrated, and is the center of the other side different from the one side of the base material layer (A layer). A silicone rubber composite having a line average roughness (Sa) of 1.0 μm or more.

Further, on one side of the substrate layer (A layer) containing a crystalline polyester resin as a main component, an undercoat layer (B layer) containing an amorphous polymer, a thin film layer (C layer) containing a silicone resin, a silicone In a method for producing a silicone rubber composite in which a silicone rubber layer (D layer) containing an elastomer resin is laminated in order and integrated, a rough surface is provided on the other side different from one side of the base layer (A layer). A method for producing a silicone rubber composite comprising a step of treating.

Furthermore, the silicone rubber composite of the present invention improves workability by making the silicone rubber composite easier to peel off during processing.

<Silicone rubber composite>
A silicone rubber composite (hereinafter also referred to as "this composite") will be described below as an example of an embodiment of the present invention. However, the scope of the present invention is not limited to the embodiments described below.

Since this composite is laminated with silicone rubber and a base layer (layer A) whose main component is a crystalline polyester resin, it does not cause wrinkles or bends, and can be easily molded when used as a release material for press molding. The productivity of the body can be improved. Furthermore, when the silicone rubber composite is wound into a roll or laminated in a leaf shape and molded, the adhesion between the silicone rubber composites, that is, the base layer (A layer) and the silicone rubber layer (D layer) can be improved.

[Base material layer (A layer)]
The main component of the substrate layer (A layer) used in the present invention is a crystalline polyester resin from the viewpoint of heat resistance and mechanical strength. Examples of the crystalline polyester resin include polyethylene terephthalate and polyethylene naphthalate. Among them, polyethylene terephthalate is preferable from the viewpoint of adhesion to other layers in addition to heat resistance, film stiffness, smoothness, commercial availability, and the like.
From the viewpoint of mechanical strength, the substrate layer (layer A) is preferably at least uniaxially oriented, more preferably biaxially stretched.

The thickness of the base material layer (layer A) is preferably 10 μm to 350 μm, more preferably 15 μm to 300 μm, even more preferably 20 μm to 250 μm. When the thickness is 10 μm or more, the occurrence of wrinkles or the like is sufficiently suppressed when another layer is laminated on the surface. On the other hand, when the thickness is 350 μm or less, the substrate layer (layer A) does not become too hard, so there is a tendency that it becomes easier to apply an undercoat layer, etc., which will be described later.

The surface roughness of the base material layer (A layer) is different from the one side on which the undercoat layer (B layer), the thin film layer (C layer), and the silicone rubber layer (D layer) are laminated. It is important that the line average roughness (Sa) is 1.0 μm or more, preferably 2.0 μm or more, and more preferably 10 μm or more. When Sa is 1.0 μm or more, the substrate layer (A layer) and the later-described silicone rubber layer (D layer) are less likely to adhere excessively when the silicone rubber composites are laminated. Therefore, when the silicone rubber composite is wound into a roll or laminated into a sheet, the substrate layer (A layer) and the silicone rubber layer (D layer) are in too close contact with each other. Problems such as the silicone rubber composite being difficult to peel off can be suppressed. This is because by roughening the substrate layer, the contact area between the silicone rubber composites, that is, between the substrate layer (A layer) and the silicone rubber layer (D layer) becomes smaller. It is thought that it becomes easy to peel even if it piles up. On the other hand, the upper limit of the center line average roughness (Sa) is not particularly limited, but is preferably 300 μm or less, more preferably 200 μm or less from the viewpoint of smoothness.
The centerline average roughness (Sa) is the average of the absolute values of the difference in height of each point with respect to the average plane of the surface, and conforms to ISO 25178.

In order to set the center line average roughness (Sa) to 1.0 μm or more, it is important to roughen the other side of the substrate layer (A layer) other than the one side. A known method can be applied to the roughening method. Specific roughening methods include physical methods such as corona treatment, plasma treatment, sandblasting, embossing and laser abrasion treatment, and chemical methods such as corrosion treatment with chemicals such as solvents. Among them, sandblasting and laser abrasion are preferable from the viewpoint of productivity.

[Undercoat layer (B layer)]
In the present invention, an undercoat layer (B layer) containing an amorphous polymer is provided on one side of the substrate layer (A layer). By using the undercoat layer (B layer), the thin film layer (C layer) can be uniformly formed.

The amorphous polymer is not particularly limited as long as it can be uniformly coated on the surface of the substrate layer (A layer), and substantially crystalline polymers such as polyurethane resins, acrylic resins, and amorphous polyester resins. It may be appropriately selected from polymers having no properties.
Specific examples include polyurethane resins obtained by linearly increasing the molecular weight of polyester resins and/or polyether resins with urethane bonds or the like, acrylic resins composed of copolymers of acrylic acid and/or methacrylic acid esters, acid components, or glycols. Examples thereof include copolyester resins whose components are composed of two or more kinds of monomers. Since these amorphous resins are applied in a thin film, they are usually diluted with an organic solvent, or emulsified or solubilized in water and adjusted to an appropriate concentration.

The undercoat layer (B layer) may have a crosslinked structure for the purpose of improving heat resistance and solvent resistance. , a hydroxyl group, an amino group, etc., and the cross-linking agent is appropriately selected from polyisocyanate, melamine, polyfunctional epoxy resins, metal compounds, and the like. In addition to the cross-linking agent, the coating liquid may contain a leveling agent such as a surfactant, an anti-blocking agent such as silica, a thickening agent, and the like.

The thickness of the undercoat layer (B layer) is preferably 0.01 to 5 μm. If the thickness of the undercoat layer (B layer) is 0.01 μm or more, it is preferable because the thickness can be easily adjusted, and the adhesiveness to the thin film layer (C layer) containing the silicone resin described later is also good. . Moreover, if the thickness is 5 μm or less, the coating of the undercoat layer (B layer) will not become difficult. From this point of view, the thickness of the undercoat layer (B layer) is more preferably 0.05 to 4 μm, more preferably 0.1 to 3 μm.

[Thin film layer (C layer)]
In the present invention, a thin film layer (C layer) is further formed on the undercoat layer (B layer). The thin film layer (C layer) contains a silicone resin, which has a high affinity for the undercoat layer (B layer), and forms a crosslinked film by heating or UV irradiation after coating, or silicone rubber. It is preferable to form a crosslinked film at the same time as the layer (D layer) is crosslinked.

Examples of silicone resins that can be used for the thin film layer (layer C) include addition-type silicone resins, condensation-type silicone resins, and UV-curable silicone resins.
Addition-type silicone resins include those obtained by using vinyl group-containing polydimethylsiloxane as a base polymer, blending polymethylhydrogensiloxane as a cross-linking agent, and reacting and curing the mixture in the presence of a platinum catalyst. Examples of condensation-type silicone resins include those obtained by using polydimethylsiloxane containing silanol groups at the terminals as a base polymer, blending polymethylhydrogensiloxane as a cross-linking agent, and heating and curing in the presence of an organotin catalyst. .

Examples of the UV curable silicone resin include those using polydimethylsiloxane containing acryloyl groups or methacryloyl groups as base polymers, those using polydimethylsiloxane containing mercapto groups and vinyl groups as base polymers, and the addition type silicone resins described above. Alternatively, a photopolymerization initiator is added to a polydimethylsiloxane containing an epoxy group that is cured by a cationic curing mechanism as a base polymer, and the composition is cured by irradiation with UV light.

In addition, the coating liquid preferably contains an additive such as a silane coupling agent for the purpose of increasing affinity with the undercoat layer (B layer). A silane coupling agent that satisfies this purpose is a compound represented by the general formula YRSiX ₃ , where Y is an organic functional group such as a vinyl group, an epoxy group, an amino group, or a mercapto group, and R is an alkylene group such as methylene, ethylene, or propylene. , X is a hydrolyzable functional group such as a methoxy group or an ethoxy group, or an alkyl group. Specific compounds include, for example, vinyltriethoxysilane, vinyltrimethoxysilane, γ-glycidylpropyltrimethoxysilane, γ-glycidylpropyltriethoxysilane, N-β (aminoethyl)-γ-aminopropyltrimethoxysilane, N- β(aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane and the like.

The thickness of the thin film layer (C layer) is preferably 0.01 to 1 μm after solvent drying. When the thickness is 0.01 μm or more, a cured film having a uniform thickness can be obtained, and a sufficient adhesive strength to the silicone rubber layer (layer D) can be obtained. In addition, since the silicone resin with the above composition generally does not have a very strong film strength, when evaluating the peel strength of the present composite, cohesive failure tends to occur in the thin film layer (layer C), but the thickness thereof is 1 μm or less. If so, cohesive failure of the thin film layer (C layer) can be suppressed, and sufficient strength can be obtained as a silicone rubber composite. From this point of view, the thickness of the thin film layer (layer C) is more preferably 0.03 to 0.7 μm, more preferably 0.05 to 0.5 μm.

[Silicone rubber layer (D layer)]
The silicone rubber layer (layer D) is characterized by containing a silicone elastomer resin.
A preferred example of a silicone elastomer resin that can be used for the silicone rubber layer (layer D) is a silicone elastomer resin containing polydimethylsiloxane as a main component.
From the viewpoint of adjusting the compression set, the silicone rubber layer (D layer) preferably contains a silicone elastomer resin containing vinyl group-containing polydimethylsiloxane as a main component. When a vinyl group is contained, the content of the vinyl group with respect to the total amount of polydimethylsiloxane is preferably 0.05 to 5 mol%, more preferably 0.5 to 4 mol%, 1 to 3 More preferably, it is mol %. When the vinyl group content is 0.05 mol %, the crosslink density of the silicone elastomer resin can be easily adjusted, and a silicone elastomer resin having a desired compression set can be obtained. On the other hand, if it is 5 mol % or less, the silicone elastomer resin is not excessively cured, which is preferable.

A commercial item can also be used as such a silicone elastomer resin. As commercially available products, a millable type silicone compound manufactured by Shin-Etsu Chemical Co., Ltd. or a millable type silicone rubber manufactured by Momentive Performance Materials can be used.

Here, the silicone elastomer resin includes reinforcing fillers such as fumed silica, precipitated silica, diatomaceous earth, and quartz powder, various processing aids, heat resistance improvers, and various additives that give functionality as an elastomer. It may contain an agent. Examples of the additives include flame retardant agents, heat-dissipating fillers, conductive fillers, and the like.

The thickness of the silicone rubber layer (layer D) is preferably 50 μm or more. When the thickness is 50 μm or more, the composite can sufficiently exhibit rubber elasticity. Moreover, the lower limit of the thickness is preferably 1.5 mm or less in terms of usage.

The silicone rubber layer (D layer) preferably has a hardness of 10 to 80, more preferably 20 to 70, when the silicone elastomer resin is cured. When the hardness is 10 or more, the composite can have sufficient handleability, and when it is 80 or less, it can have sufficient elasticity.
The hardness measurement method conforms to JIS K6301 spring hardness test type A.

[Lamination structure]
The laminated structure of the silicone rubber composite of the present invention is formed by laminating in the order of A layer/B layer/C layer/D layer and integrating them. Alternatively, if necessary, another layer such as a protective layer may be laminated on the surface of the silicone rubber layer (D layer).

[Peeling property]
The peel force between the silicone rubber composites of the present invention at room temperature is preferably 0.03 mN/20 mm or less, more preferably 0.02 mN/20 mm or less. On the other hand, the lower limit is not particularly limited from the viewpoint of peeling properties.
When the composite is used as a release material, the lower the peel force at room temperature, the less force is required when peeling the composite from each other during processing of the composite. It is possible to suppress defects such as deformation of the body. Above all, the present composite can suppress the above problems and have low peeling properties even when the adhesive silicone rubber layer (D layer) is present.
The peel strength at room temperature shall be measured by the method described in Examples below.

<Method for producing silicone rubber composite>
In the method for producing a silicone rubber composite of the present invention, an undercoat layer (layer B) containing an amorphous polymer and a silicone resin are provided on one side of a substrate layer (layer A) containing a crystalline polyester resin as a main component. A thin film layer (layer C) containing a silicone elastomer resin and a silicone rubber layer (layer D) containing a silicone elastomer resin are laminated in this order and integrated.

First, a coating liquid as an undercoat layer (B layer) is applied to one side of the substrate layer (A layer) containing the polyester resin as a main component, then dried, and if necessary, thermally crosslinked. to form an undercoat layer (B layer). As a coating method, a known method suitable for the coating liquid can be applied, and it may be applied to the base layer (A layer) stretched in a separate step, or to an unstretched sheet of the base layer (A layer). The undercoat layer (B layer) may be formed by applying the coating solution directly and then stretching the coating. For the purpose of improving the leveling property and adhesion of the coating liquid, the surface to be coated may be subjected to surface treatment such as corona treatment in advance.

Next, a thin film layer (C layer) is applied on the undercoat layer (B layer). As with the undercoat layer (B layer) described above, the coating method is not particularly limited as long as a thin film can be obtained with high precision, and known methods can be used.

Further, the silicone rubber layer (layer D) containing silicone elastomer resin is preferably laminated by the following method. First, an uncrosslinked silicone elastomer resin is laminated on a thin film layer (layer C) containing a silicone resin. As a lamination method, it is preferable to form an uncrosslinked silicone elastomer resin into a sheet by extrusion molding, injection molding, calendar molding, press molding, or the like, and then laminate it on the thin film layer (layer C). Alternatively, a method of forming a film directly on the thin film layer (C layer) by a known coating method may be used.

Next, the silicone rubber composite of the present invention can be obtained by curing the uncrosslinked silicone elastomer resin. Examples of means for curing the silicone elastomer resin include a method of adding a curing catalyst, a method of heating at a high temperature, a method of adding a cross-linking agent, and a cross-linking method by irradiation with radiation.

Among others, the silicone rubber layer (D layer) of the composite is preferably a radiation-cured material cured by irradiation with radiation. Curing by radiation irradiation is preferable because there is no concern that the heat resistance and light resistance reliability will be impaired by residues of catalysts and cross-linking agents. Moreover, since heat is not applied during curing, there is no fear of thermal deterioration, which is preferable.

Examples of radiation include electron beams, X-rays, and γ-rays. These radiations are widely used in industry and are readily available and energy efficient methods. Among these, it is preferable to use gamma rays from the viewpoint of almost no absorption loss and high permeability.

The irradiation dose of γ-rays can be appropriately selected and determined depending on the type of resin, the amount of cross-linking groups, and the type of radiation source. In this complex, for example, the irradiation dose of γ-rays is preferably 20 to 150 kGy. If the irradiation dose is 20 kGy or more, the silicone rubber layer (D layer) can be sufficiently cured, and as a result, a desired compression set can be obtained. On the other hand, if the irradiation dose is 150 kGy or less, an increase in low-molecular-weight components due to decomposition reaction can be suppressed. From this point of view, the irradiation dose is more preferably 30 to 120 kGy, more preferably 40 to 110 kGy.

In addition, in selecting the irradiation dose, it is necessary to consider the radiation resistance of the plastic film used as the substrate layer (layer A) in addition to the crosslinking density of the silicone elastomer resin. In this respect, the crystalline polyester resin used in the present invention is generally excellent in resistance to radiation and is a base material that is extremely suitable for the purpose of the present invention.

In the present invention, the expression "main component" includes the meaning of permitting the inclusion of other components within a range that does not interfere with the function of the main component, unless otherwise specified.
At this time, although the content ratio of the main component is not specified, the main component (when two or more components are the main component, the total amount of these) is 50% by mass or more in the composition, preferably 70% % by mass or more, particularly preferably 90% by mass or more (including 100%).
In addition, in the present invention, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less", "preferably larger than X" and "preferably is less than Y".
In addition, in the present invention, the expression "X or more" (X is any number) includes the meaning of "preferably greater than X" unless otherwise specified, and "Y or less" (Y is any number ) includes the meaning of "preferably smaller than Y" unless otherwise specified.

In general, "sheet" is defined in JIS as a thin, flat product whose thickness is smaller than its length and width. A thin flat product with an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (JIS K6900: 1994). However, the boundary between "sheet" and "film" is not clear, and there is no need to distinguish between the two in terms of wording in the present invention. The term "sheet" also includes "film".

Examples will be described below, but the present invention is not limited to these.

(Example 1)
A biaxially oriented polyethylene terephthalate film (manufactured by Mitsubishi Chemical Corporation, S-100) having a thickness of 50 μm was used as the substrate layer (layer A). One side of the substrate layer (layer A) was roughened by sandblasting, and the center line average roughness (Sa) was 3.3 μm.
An undercoat layer (B layer), a thin film layer (C layer), and a silicone rubber layer (D layer) are laminated in this order on a surface different from the surface roughened by the substrate layer (A layer) by the method shown below, A silicone composite was obtained by integrating.

[Undercoat layer (B layer)]
Amorphous polyester resin, (manufactured by Toyobo Co., Ltd., trade name: Vylon 240) 15 parts by weight, polyisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate L) 2 parts by weight, solvent (MEK / toluene = 1/4 (mass ratio)) was diluted to 85 parts by mass to prepare a coating liquid. This was applied to the surface of the substrate layer (A layer) by a bar coater so that the thickness after drying was 1.0 μm, and dried and crosslinked in a gear oven at 100° C. for 10 minutes.

[Thin film layer (C layer)]
20 parts by mass of a condensed silicone resin composition (manufactured by Dow Corning Toray Silicone Co., Ltd., trade name: SRX290) and 1.2 parts by mass of a curing agent (manufactured by Dow Corning Toray Silicone Co., Ltd., trade name: SRX242C) A coating liquid was obtained by diluting with 79.8 parts by mass of a solvent (toluene). This was applied to the surface of the undercoat layer (layer B) with a bar coater so that the thickness after drying was 0.1 μm, and dried and crosslinked in a gear oven at 100° C. for 10 minutes.

[Silicone rubber layer (D layer)]
A millable silicone compound (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KE-561U) was press molded to obtain an uncrosslinked silicone elastomer resin sheet having a thickness of 3 mm. The resin sheet was laminated so as to be in contact with the surface of the thin film layer (layer C), and a silicone rubber composite was produced at room temperature under a press pressure of 50 kg/cm ² .
The surface of the silicone rubber layer (layer D) of the silicone rubber composite was irradiated with an electron beam of 100 kGy using an electron beam irradiation apparatus with an acceleration voltage of 200 kV to form a silicone rubber layer (layer D) with a hardness of 55.

The obtained silicone rubber composite was subjected to the following measurements. Evaluation results are shown in Table 1.
(1) Center line average roughness (Sa)
The center line average roughness (Sa) of the surface of the substrate layer (A layer) on the opposite side of the silicone rubber layer (D layer) was measured using a surface roughness measuring instrument (SE-3F, manufactured by Kosaka Laboratory Co., Ltd.). ) was used.
That is, a portion having a reference length L (2.5 mm) is extracted in the direction of the center line from the cross-sectional curve of the sample film obtained by measurement, and the center line of this extracted portion is the x-axis, and the direction of the longitudinal magnification is the y-axis. , and the roughness curve y=f(x), the value given by the following formula is expressed in [μm]. Ten cross-sectional curves were obtained from the surface of the sample film, and the center-line average roughness was expressed as the average value of the center-line average roughness of the sampled portions obtained from these cross-sectional curves. The tip radius of the stylus was 2 μm, the load was 30 mg, and the cutoff value was 0.08 mm.

(2) Peeling properties After preparing two silicone rubber composites cut to a size of 20 mm × 120 mm, the substrate layer (A layer) of the silicone rubber composite and the silicone rubber layer of another silicone rubber composite (Layer D), and the peel strength at room temperature was measured. For peel strength measurement, a tensile tester ("Intesco model 2001" manufactured by Intesco Co., Ltd.) was used, and T-shaped peeling was performed at a tensile speed of 300 mm/min.

(Example 2)
A silicone rubber composite was produced in the same manner as in Example 1, except that the surface was roughened by laser abrasion instead of sandblasting. Evaluation results are shown in Table 1.

(Comparative example 1)
A silicone rubber composite was produced in the same manner as in Example 1, except that one surface of the substrate layer (layer A) was not roughened by sandblasting. Evaluation results are shown in Table 1.

When the base material layer (A layer) is roughened as in the examples, the release properties between the base material layer (A layer) and the silicone rubber layer (D layer) are improved, and during processing As a result, the silicone rubber composites are easily separated from each other, and the silicone rubber composites have sufficient productivity.
On the other hand, when the substrate layer (A layer) was not roughened as in the comparative example, the release properties between the substrate layer (A layer) and the silicone rubber layer (D layer) were insufficient. In addition, the silicone rubber composites are less likely to separate from each other during processing, and there is a risk of deterioration in productivity.

The silicone rubber composite of the present invention has excellent properties as a release material during press molding. For example, it can be suitably used for manufacturing moldings such as display/touch panel related product members such as ICs, semiconductors, and passive components incorporated in electric/electronic products, and LED lighting product members.

Claims (6)

An undercoat layer (B layer) containing an amorphous polymer, a thin film layer (C layer) containing a silicone resin, and a silicone elastomer resin are provided on one side of a substrate layer (A layer) containing a crystalline polyester resin as a main component. A silicone rubber composite formed by laminating and integrating a silicone rubber layer (D layer) containing
A silicone rubber composite having a center line average roughness (Sa) based on ISO 25178 of 1.0 μm or more on the other side of the substrate layer (A layer), which is different from the one side. 2. The silicone rubber composite according to claim 1, wherein the substrate layer (A layer) is oriented in at least one axial direction. The silicone rubber composite according to claim 1 or 2, wherein the silicone rubber layer (layer D) is a radiation-cured product. A release material using the silicone rubber composite according to any one of claims 1 to 3. An undercoat layer (B layer) containing an amorphous polymer, a thin film layer (C layer) containing a silicone resin, and a silicone elastomer resin are provided on one side of a substrate layer (A layer) containing a crystalline polyester resin as a main component. In the method for producing a silicone rubber composite formed by laminating and integrating silicone rubber layers (layer D) containing
A step of roughening the other side of the base material layer (A layer) other than one side , and the center line average roughness (Sa) of the multi-sided side based on ISO 25178 is 1.0 μm or more. A method for producing a silicone rubber composite. 6. The method for producing a silicone rubber composite according to claim 5 , wherein the roughening treatment is sandblasting or laser abrasion treatment.